Narcolepsy is a neurological disorder of unknown origin that afflicts about 1 in 1000 Americans. Clinically, narcolepsy first appears in adolescence or young adulthood as irresistible urges to sleep. Auxillary symptoms are cataplexy, hypnagogic hallucinations and sleep paralysis. The disease has been linked to problems ranging from "under achievement in school" to "unhappy marriage" to "death in traffic accidents." The research is designed to evaluate the most frequently used treatments for this disorder. We will complete a double-blind, multiple-drug, multiple-dose level study on drug therapy in narcoleptic patients. A repeated-measures design has been employed and a normal control group is being studied to assess the effect of repeated measurement and to gather normative data. We plan to complete studies comparing the relative effectiveness of four drugs in common use for control of excessive somnolence in narcolepsy: pemoline, methylphenidate protriptyline, and dextroamphetamine.